This invention relates to a recording and reproducing device for recording data on an optical disk and reproducing data recorded on the optical disk, a recording device exclusively used for recording data on an optical disk, a reproducing device exclusively used for reproducing data recorded on the optical disk, and a replacement processing method for effecting the replacement process for a defect area or defect areas in the optical disk device.
Conventionally, an optical disk device for recording data on an optical disk having recording tracks or reproducing data recorded on the optical disk using laser light emitted from a semiconductor laser oscillator mounted on an optical head has been put into practical use.
With the above optical disk device, data is recorded on the optical disk in units of one ECC block, each block being constructed by a plurality of sectors.
In this case, there is provided a process for determining whether or not data is correctly recorded in units of one sector at the time after the manufacturing time or the initial time, such as the application starting time. If a sector with a defect is detected by the above determination process, the process includes treating the sector as an unusable block, and recording data into a sector in a different area for replacement.
In this case, if data recorded on the different area sector is not simultaneously reproduced when one ECC block is reproduced, reproduction of the whole ECC block cannot be effected. That is, originally, the sectors of one ECC block can be successively reproduced, but in this case, it becomes necessary to reproduce the sector for replacement in the course of reproduction of the ECC block and then successively reproduce the sectors of the original ECC block. Therefore, the reproduction speed is lowered.